Water cooler



FIG. 1 is a front, side perspective view of a water cooler showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a rear elevational view thereof; and,

FIG. 7 is a right side elevational view thereof.

The broken lines are included for the purpose of illustration and form no part of the claimed design. 

The ornamental design for a water cooler, as shown and described. 